[peter47]

Somewhere way back, SCHS posted about finding quite a discrepancy between the car's claimed average fuel consumption, and what he found by actual measurement. I found this a bit of a challenge, so started doing the same. Thus far, over just two tank fill-ups to the kick-off point, zeroing the trip meter each time, mine has averaged out at an actual 9.2 L/100Km, against the car computer's claim of 8.2 L/100Km.

Now while not spot on, I never expected it would be, but it's not too bad if it is only optimistic to the tune of 1 extra litre of fuel consumed over 100km..?
However, to be fair, I also do a lot of shortish trips and most of my distance covered is on roads with speed zones between 40kph and 80kph, with lots of roundabouts, and we only occasionally get off the island and onto freeway type roads of up to 110kph. So I wasn't expecting spectacular figures. Anyone else checked..? SCHS, any further progress figures..?

 

[iminhell]

In freedom units,
9.2 = 25.5MPG
8.2 = 28.5MPG

With mine I've found short trips really do kill MPG's. It takes quite a bit of steady state highway driving to overcome a few short trips. Kinda makes a guy wonder what lean burn programming is going on in the cars brain.

 

[Futures trader]

My dash display says I’m getting 31 mpg but I’m only getting 24.

 

[peter47]

My dash display says I’m getting 31 mpg but I’m only getting 24.

One suspects the car economy computation, however it's done, is set up to be...let's just say...optimistic..? A bit like the speedo reading. Do you folk have an inbuilt over-read in the speed indication. Here in Aus they seem to have been programmed to over-read by 4kph, no matter what the speed, so it's not simply a percentage error. That is at 100kph you are actually, by GPS, doing only 96. Same 4kph difference right through the speed range..? I might start a new thread on this. I think Speedtek has indicated something similar in the Canadian models..?

 

[NumbNuts]

Being in USA I have checked mine on a regular basis. It's usually off by 1 or 1.5 mpg. I ignore the real time mpg and only pay attention to the overall average. I do a lot of highway driving so with my SX I'm averaging about 30-31mpg, which I'm very happy with it being an Allwheel drive small suv.

 

[ta2102]

Being in USA I have checked mine on a regular basis. It's usually off by 1 or 1.5 mpg. I ignore the real time mpg and only pay attention to the overall average. I do a lot of highway driving so with my SX I'm averaging about 30-31mpg, which I'm very happy with it being an Allwheel drive small suv.

I'm averaging the same, roughly. But I'm not an AWD so maybe I should be a little less heavy on the pedal. It's anywhere from 29-32mpg on the longterm averages.

 

[iminhell]

So where is the car grabbing speed from? is it the same place as the miles? Presumably it is. It might be from the wheel speed sensors or it could be from a VSS in the transmission ... and which transmission do you have, CVT or DCT?

But if the speed is off it's a safe bet the fuel economy calculation is also off (by the same factor). I'm not going to go through and do the math.

 

[Fogwash HT]

It's time for me to do some manual calculations as my 23 LX AWD is reading an average accumulated mpg of 34 with some trips being as high as 40. I cannot tell if I am in the goldilocks zone of trip length and speed, am a gentle driver, the number is off, or it's just great gas mileage.

 

[peter47]

It's time for me to do some manual calculations as my 23 LX is reading an average accumulated mpg of 34 with some trips being as high as 40. I cannot tell if I am in the goldilocks zone of trip length and speed, am a gentle driver, the number is off, or it's just great gas mileage.

Then there's no avoiding it. You need to tank up to the kick-off - zero the trip meter - you can't loose the overall distance reading, so relax - just hit and hold the 'ok' button on the wheel a second or two - then tank up and take trip reading again when nearly empty - do this several times, then average out doing the maths. Let us know what you find.

 

[Speedtek22]

Road Trip is an excellent app for the iPhone, I’ve been using it for years…I don’t know if they have an android version.

‎Road Trip HD

‎Road Trip HD is the fastest and easiest app for tracking of your car’s fuel economy, maintenance history, and expenses. Remember to checkout Road Trip Lite and Road Trip for the iPhone. _____________________________ "There’s a ton of MPG apps on the App Store but Road Trip is the best...

apps.apple.com

 

[iminhell]

E50 average MPG is 18.7 combined.
Just throwing that out there. LOL